So the Mouse Guard source book has entries on some wild animals people can use for their encounters. Here is a sample entry:
The green snake is a beautiful snake named for its brilliant scales. It hunts insects, but is otherwise harmless. They grow to about three mouse lengths, so it can be frightening to wake up and find one curled around your campfire!
Green Snake Nature 4
Insect Hunting, Hiding, Slithering
So it has a set of actions that are within its nature to do. That's fine, but what if the players want to try and talk to it? Naturally, its considered a Conflict, but if it's, say an argument, shouldn't the snake, being a snake, have some points in Deceiver? or maybe Persuader?
What should I, as a GM, do? Put my own points into those skills, keeping in mind the balance of the game and the nature of the creature, or just default anything not included in the book to Nature, as the book itself suggests? I feel some animals should have some skills they don't, like, say, the snake and Deceiver/Persuader.
Or is the book trying to tell me "Since I don't include some skills in the creature entry, that means those skills are outside the creatures Nature, so if it tries to do those skills, it should roll against Nature"? (I think that's what you do when you do something against your Nature anyway)